Improvement in machines for screw-threading tubes



, HEA ;P. Machines for Screw-Threading Tubes.

Patented Aug. 4,1874.

Wiinesses,

THE GRAPHIC C0 PHOT0LITH.39&4I PARKPLACEJLY.

' NITED STATES PATENT OFFICE.

JOSHUA HEAP, OF OLDHAM, GREAT BRITAIN.

IMPROVEMENT IN MACHINES FOR SCREW-THREADING TUBES.

Specification forming part of Letters Patent No. 153,770, dated August 4, 1874; application filed November 7, 1873.

To all whom it may concern Be it known that I, JOSHUA HEAP, of Oldham, in the county of Lancaster, in the Kingdom of Great Britain, have invented an Improved Machine for Threading Tubes and tBolts, of which the following is a specifica- My invention relates to apparatus, designed more particularly for threading tubes, but also applicable to be used for threading bolts.

The object of my invention is to etfect such threading with greater ease and rapidity than when the threading-stocks are used. The tube to be threaded is held by a vise, and arotatin g cutter-head, carrying the cuttingdies, ofl'ects the threading.

The apparatus is represented in the accompanyin g drawing, wherein Figure 1 is a vertical longitudinal section through the center otthe cutter-head and the holding-vise. Fig. 21s a cross-section on the line Fig. 3 is a s de elevation. Fig. 4 is a back-end elevawon with the covering-plate b removed, and Fig. 5 is a front elevation.

ln the said figures, A is the framing, B is a vise to hold the tubes during the operation of threading, and O is a revolving cutter-head. The vise is formed in the end of the framing,

which is turned out to receive a ring, a, seen also in Fig. 4. The ring a is formed with three cam-shaped inclines, which act upon three griping-pieoes, c c c, which are fitted to slide up and down in grooves formed in the framing. The periphery of the said ring is formed with worm-teeth, with which gears a worm, d, which is mounted in a bored orifice formed in the side of the framing. When the said worm is turned,by means of the handle a, the ring a is caused to revolve in the direction of the arrow, and, acting on the gripingpieces, forces them toward the tube, represented by f, and the griping-pieces are thus caused to gripe the tube, and to hold it firmly. A plate, 9, which is screwed to the ring a, has attached to it an annular plate with raised edges h, which are curved'to correspond with the cam-shaped inclines of the ring a. These edges work in notches in the griping pieces, and serve to draw them back when the ring a is turned in a direction contrary to that indicated. The cutter-head O is formed with a upon the tube.

sleeve, 1), which is turned and fitted to revolve within the bush 1', which is fixed in the framing. .A front view of the said cutter-head, with the covering-plate j removed, is seen at Fig. 2. The said cutter-head is turned out to receive a cam-ring, k, which acts upon the cutting-dies H1 in the same manner as the ring a acts on the pieces 0 c c. The said dies are, however, arranged so that the sides on which the cutting-edges are formed are radials from the central orifice. The dies are drawn back by a plate screwed to the ring 70, as in the case of the griping-picces in the vise. Spur-teeth are formed on the inner edge of the ring k, and a spur-pinion, n, which can be turned with a handle or key, gears with the said teeth, and the said ring may thus be turned in one direction or the other, according as the dies are to be forced toward the tube to be threaded or to be withdrawn therefrom. Spur-teeth are also formed on the outer periphery of the cutter-head, and a long pinion or ribbed shaft m gears therewith. A

revolving motion is imparted to the shaft m by means of the bevel-gearing 0 and. the handle 17, so that when the said handleis turned the cutter-head is caused to revolve. (See Fig. 5.) The bush vlis tapped to receive two threaded collars, r 8, one collar having a finer thread than the other one. The bush and collars may be changed when other threads have to be cut. Either of the said collars can be fastened to the shank of the cutter head by which will be governed by the thread of whichever collar may be temporarily secured to the same, a corresponding thread being cut The screw on the said collar may be loosened when the dies have got sufficient hold, and the cutting of the screw be continued without the aid of the said collar. A cutter, t, is fitted to slidein a groovein the plate j, which is fixed to the cutter-head, as seen in Fig. 6, and the said cutter may be set up or drawn back by means of the screw it.

This cutter is useful for cutting ofif the ends of tubes, or for cutting ofl lengths of tubes. Bolts may be threaded in the machine, suitable dies being fitted in the cutter-head. When a machine is specially adapted for threading bolts, it may be necessary to modify the forms of the griping-pieces in the vise, or to substitute a different description of bolding-vise. The arrangements for giving motion to the revolving cutter-head may be varied, as, for example, bevel-gearing, or a Worm and Wheel may be employed, instead of spur-gearing.

the purpose specified.

JOSHUA HEAP. Witnesses EDWARD K. DUTTON, HUGH G. GRANT. 

